Fix checkstyle

Author: winterhazel

framework/quota/src/main/java/org/apache/cloudstack/quota/QuotaManagerImpl.java

@@ -53,7 +53,6 @@
 import org.apache.cloudstack.quota.vo.QuotaBalanceVO;
 import org.apache.cloudstack.quota.vo.QuotaTariffUsageVO;
 import org.apache.cloudstack.quota.vo.QuotaTariffVO;
-import org.apache.cloudstack.quota.vo.QuotaUsageJoinVO;
 import org.apache.cloudstack.quota.vo.QuotaUsageVO;
 import org.apache.cloudstack.usage.UsageUnitTypes;
 import org.apache.cloudstack.utils.bytescale.ByteScaleUtils;